The present disclosure relates to an information processing apparatus, a communication method, a power storage device, and an electric vehicle using power from the power storage device.
In recent years, uses of a secondary battery, such as a lithium-ion battery, have been rapidly expanded into uses for power storage of storage device, an automobile storage battery, and the like, where the secondary battery is combined with new energy systems, such as a solar battery and wind power generation. To generate high power, when a number of electrical storage elements, such as battery modules (also referred to as electric cells, or simply referred to as cells, in the following description, appropriately referred to as battery cells), are used, a configuration in which a plurality of storage modules are connected in series is employed. The storage module configures a battery block by connecting a plurality of battery cells, for example, four battery cells in parallel and/or in series. A number of battery blocks are housed in an exterior case to configure the storage module (also, referred to as a battery pack).
Further, a power storage device has been known, which connects a plurality of storage modules, and has a common control device (appropriately referred to as a main controller) to the plurality of storage modules. Each of the storage modules includes a module controller, and the module controller communicates with the main controller via a communication path.
The module controller monitor includes a monitoring circuit and a microcomputer (appropriately, referred to as a sub microcontroller unit) in order to monitor the status of the battery cells and to detect an error. The monitoring circuit monitors the voltage of each battery cell, compares a predetermined threshold value and the voltage of the battery cell with a comparator, and outputs a detection signal (for example, one-bit detection signal) that indicates normal/error.
At the time of charging, the voltage of each battery cell is compared with a predetermined value, and a detection signal that indicates whether the voltage is an overvoltage (appropriately, referred to as OV) is generated. At the time of discharging, the voltage of each battery cell is compared with a predetermined value, and a detection signal that indicates whether the voltage is an under voltage (appropriately, referred to as UV) is generated. At the time of charging/discharging, a current value that flows in a battery cell is compared with a predetermined value, and a detection signal that indicates whether the current value is an overcurrent (appropriately, referred to as OC) is generated. Further, at the time of charging/discharging, the temperature of each battery cell is compared with a predetermined value, and a detection signal that indicates whether the temperature is in an overheat status (appropriately, referred to as OT) is generated.
Further, a balance adjustment is performed in which a voltage and a current in each battery cell are supplied to the sub microcontroller unit of each module, and voltages of a plurality of battery cells are equalized. The above-described detection signals from the monitoring circuit are supplied to the sub microcontroller unit. Further, the detection signals are transmitted from the module controller to the microcomputer (appropriately, referred to as a main microcontroller unit) of the main controller via a communication path. The main controller receives the detection signals from each storage module and controls a charge/discharge operation.
Therefore, data communication between the sub microcontroller unit of the module controller and the main microcontroller unit of the main controller is absolutely necessary for a stable operation of the power storage device system. For example, Patent Literature 1 described below discloses that a power inverter (inverter) determines there is an error when an error detection signal is supplied from a protection circuit of an insulated gate bipolar transistor (IBGT) to a command unit at least twice.